In a traditional AM receiver, there are abrupt changes in direct current (DC) and amplitude of the output signal and thus affects the sound quality of the output signal. The abrupt changes can be caused by the gain from an automatic gain control (AGC) module, an effect of (1−e−ωHPFt) in an AM high-pass filter module and an effect of (1−e−ωLPFt) in the AM low-pass filter module in the receiver. For example, if an amplitude value of an input signal changes from A to B due to the gain change from the AGC module, the output signal of the AM receiver can have an abrupt change
      B    -    A    Ain DC of the output signal and an abrupt change B/A in amplitude of the output signal.
To eliminate these abrupt changes, a new method and device for improving acoustics of AM demodulation output signal may be necessary.